[3.5.0-beta.3] The engine brakes do not engage.

Aitor

Re: [3.5.0-beta.3] Problems found with this version

Good morning @dc42,

I wanted to ask if you had the opportunity to review or note a problem I am having with the motor brakes in this beta version. In short, the motor brakes do not activate when I execute M84, which causes my Z axis to fall.

I am using the Duet6HC electronics with two Duet3HC expansions.

On the other hand, during printing, something quite strange happens. At the end of the first layer, the motor brakes are heard and the second layer does not begin in the expected place. This behavior is especially odd since, in principle, the motors should not disable at any point. I have reviewed my G-code and I do not see any unusual commands. I want to emphasize that the brakes are not heard in the following layers and they do not seem to get locked, as the print continues normally, except for the mentioned jump.

In addition, I want to point out that I am using mesh compensation and "baby steps". The only difference compared to other prints where I did not notice this jump is that now my "baby step" value is positive.

If you need more information or need me to clarify any point or perform any additional testing, do not hesitate to tell me.

Best regards,
Aitor

dc42

@Aitor

What firmware.versions are you running on each board?
Does the X axis fall just a little, or all the way to the bottom?

Aitor

Hello @dc42,

In reference to the first point:

M115 B0
FIRMWARE_NAME: RepRapFirmware for Duet 3 MB6HC FIRMWARE_VERSION: 3.5.0-beta.3 ELECTRONICS: Duet 3 MB6HC v1.02 or later FIRMWARE_DATE: 2023-04-14 11:28:15

M115 B1
Duet EXP3HC rev 1.02 or later firmware version 3.5.0-beta.3 (2023-04-13 18:42:24)

M115 B2
Duet EXP3HC rev 1.02 or later firmware version 3.5.0-beta.3 (2023-04-13 18:42:24)

In reference to the second point:

My Z-axis manages both the Y-axis and the X-axis, meaning that the bed remains stationary and does not move. The complete kinematics are based on spindles. For the Z-axis, all four motors are equipped with brakes to prevent them from falling. Normally, they do not completely collapse, but they may tilt towards the heavier side depending on the position of the Y-axis, which disrupts the linearity of the Z-axis.

If you have any additional questions, please feel free to reach out to me. Furthermore, if you require any videos or photos, I would be glad to provide them privately.

Best regards,
Aitor